Motor grader moldboard



Feb. 4, 1969 i J. L. STRABALA ET AL 3,

' MOTOR GRADER MOLDBOABD Filed July 19,1967 7 Sheet i 12/ INVENTORS JOSEPH L. STRABALA I F/PA/VK A. 690055 BY Z7 9 9,4,4, PW

ATTORNEYS Feb. 4, 1959 STRABALA ET AL 3,425,497

MOTOR GRADER MOLDBOARD Filed July 19, 1967 Sheet L of 2 (@i INVENTORS JOSEPH L. STRABAL/l ig: Z3 FRANK 4. GROOSS 25' BY 3 $1,...0L y yuq. +14

ATTORNEYS United States Patent 6 Claims ABSTRACT OF THE DISCLOSURE Motor graders have conventionally used a unitary moldboard or blades mounted on the grader circle for manipulation by the operator. Greater flexibility can be provided by hinging the moldboard so additional configurations are possible, as long as suspension rigidity between the blade and circle is maintained. A unique hinged blade structure for use in combination with a grader circle can be fabricated by joining two blade wings endwise with a hinged connection to form a moldboard, mounting slide rails on the backs of the wings, swingably supporting the slide rails in two guide brackets about an upright axis at spaced locations, mounting a shift jack between one of the wings and its supporting guide bracket for laterally shifting the mold-board, mounting the guide brackets on the circle in a pivoted connection having an axis transverse to such upright axis, and positioning a jack between the hinged connection of the wings and the circle through which the moldboard may be changed in angular disposition by operating the jacks.

Background of the invention Hinged blades or moldboards are not new and have been employed with or in various types of earthmoving vehicles. For example, see U.S. Patent 2,749,631 issued to Thompson, and U.S. Patent 3,026,662 issued to Cunningham. However, such structures have not been readily employed with motor graders in a manner which will complement its existing moldboard control structure, i.e. grader circle and control linkages, without impairing their normal moldboard control features in any way.

U.S. Patent 3,164,915 issued to Benner shows a conventional motor grader with the circle supported on the grader frame through controlled linkages. These linkages can be employed to rotate, lift, lower, tilt, side shift and generally manipulate the circle relative to the graders frame to control the moldboard attached to the circle. Moldboard control through this arrangement is accurate and precise allowing cuts with the moldboard to be maintained within inch.

With the instant invention, the conventional moldboard control is maintained by coupling the hinged blade structure to the circle in a manner it can function like a conventional unitary moldboard through rigid but adjustable links and yet be converted to V configurations to aflord the operator additional modes of control. Economy is maintained through the structures simplicity as an added advantage.

Also the hinged moldboard structure can be marketed as a kit, converting existing motor graders to a hinged moldboard type or used as an interchangeable attachment with a conventional moldboard attachment on motor graders since only a nominal modification of the circle is necessary for the hinged moldboard.

Summary of the invention A unique hinged moldboard structure in combination with a motor grader circle can be fabricated with a pair of hinged blade wings joined endwise in a hinged con- 3,425,497 Patented Feb. 4, 1969 nection, slide rails mounted on the backs of said wings, two spaced guide brackets slidably receiving said slide rails and swingable about an axis parallel to the axis of said hinged connection, jack means connected between one of said guide brackets and its associated wing for slidably shifting the wing relative to said bracket, mounting means swingably supporting said guide brackets, said mounting means being pivoted to said circle about an axis transverse the swing axis of said guide means, locating means to fixedly position said mounting means, and positioning means connected between said hinge connection and said circle through which the location of said hinged connection may be adjusted.

Brief description of the drawings FIG. 1 is a perspective of a grader circle having the hinged moldboard structure mounted thereon;

FIG. 2 is a top view of the circle and hinged moldboard structure illustrated in FIG. 1 with a conventional grader drawbar attached to the circle;

FIG. 3 is a top view of a high ground clearance version of the hinged moldboard structure, with broken lines indicating several of the many moldboard configurations possible;

FIG. 4 is an elevation of the version shown in FIG. 3 with the moldboard shown in section; and

FIG. 5 is an elevation similar to that illustrated in FIG. 4 with parts broken away to disclose additional detail.

Description of an embodiment A unique hinged moldboard structure 10 is shown in FIG. I mounted on the spaced shank arms 11 of a conventional motor grader circle 12. FIGS. 2, 3 and 4 illus trate the attachment of a drawbar 13 to the circle with clamps 14. U.S. Patent 3,164,915 issued to Benner et a1. is referred to for a disclosure of the balance of the attaching linkages between the circle and the grader frame. This patent illustrates how the drawbar and circle are connected to the frame.

Moldboard 20 is composed of two vertical, arcuate wings 21 which are joined endwise in a hinged connection 22. The bottom edge of each wing is provided with replaceable cutting edge 23 and spaced slide rails 24 are mounted longitudinally on the back of each wing.

Heavy guide brackets 25 located at space locations near the foot of each shank arm 11 of the circle receive in their slotted C-shaped guide portion the slide rails of the associated wing. Mounted in this manner the wings slide longitudinally relative to its guide bracket while being rigidly supported adjacent to the foot of each shank arm 11.

One of the wings, so mounted, has a jack 26 mounted between its outboard end on lugs 27 and its guide bracket so the operator can rigidly fix the position of one wing relative to its guide bracket. The opposite wing is allowed to float in its guide bracket to allow it to slidably adjust for different blade positions, more fully explained subsequently.

Each guide bracket is swingably supported in a mount 28 through an upright pivot pin connection 29, which allows an adjustment of the brackets for the different angular disposition of the wings of the moldboard. Each of the mounts is, in turn, pivoted with pins 30 adjacent to the foot of one of the shank arms, with the axis of these pins transverse to the pivoted pin connection between the bracket and its mount. Jacks 31 connected between the top of each mount and a forward portion of the circle operate in unison to control the position of the upright pivot pin connection with reference to vertical by positioning the mounts.

If the wings of the moldboard are aligned actuations of the jacks 31 will change the pitch of the moldboard;

however, if the moldboard is in a V condition this actuation will raise or lower their hinged connection 22 with reference to the outboard ends of the joined wings, depending on the direction of the jacks, due to the support of the wings in the guide brackets.

The V of the moldboard is mainly controlled by a jack 35 having its rod 36 connected to the hinge pin 37 in a ball socket type connection in the hinged connection 22 and its cylinder 38 gimbal mounted in a U-shaped support frame 39. This support frame is mounted on the inside of the shank arms of the circle so it becomes integral with the circle. The gimbal mount 40 of the jack allows it to follow the hinged connection 22 from side to side and up and down without binding.

In FIGS. 3, 4 and an alternate gimbal mount 40 is illustrated with a high clearance U-shaped support frame 39a. The angular change in position of jack 35 can be seen in FIG. 5, by referring to the broken lines 41, as the moldboard 20 is changed in its V configuration.

A full gimbal mount could be eliminated if the U- shaped frame 39 is connected to the mounts 28 which are attached to the shank arms of the circle. This, however, in some moldboard configurations causes the U-shaped frame to drag on the ground. Further, the gimbal mount actually strengthens rigidity of the moldboard in V configurations since it provides a vertical component holding the hinged connection from moving in locations above or below the outboard ends of the wings due to cutting loads on the moldboard.

Also, FIGS. 3 and 4 show lateral shifting jack 26 modified to fit into the associated guide bracket to increase lateral shift.

In the above structure when jacks 26, 31 and 35 are hydraulically locked in a position, the moldboard, in any configuration, is rigidly fixed relative to the circle of the motor grader. Jack 35 can be actuated to control the V of the moldboard as can be seen by the broken lines in FIG. 3. In any V configuration the moldboard can be shifted laterally with jack 26 which will change the V angle due to the arcuate travel of the hinged connection 22 held by gimballed jack 35. However, jack 35 may then be used to relocate the hinged connection to achieve the desired angle between the wings.

The structure depicted allows the moldboard to be used to make a crown or a V cut in a single pass. For example, if the moldboard is in the V configuration depicted by broken lines 42 in FIG. 3, mounts 28 may be tipped forward which will lower the hinged connection beneath the outboard ends of the wings in a plowing configuration. If the moldboard is in the V configuration depicted by broken lines 43 the hinged connection would have been raised relative to the outboard ends of the wings for a crown cutting configuration. Thus it is possible to cast earthen material toward the hinged connection or away from it in crown or V cut configuration by manipulating the jacks.

Whatever the moldboard configuration selected by the operator, he will be able to further manipulate the moldboard by controlling the circle in the conventional manner.

The above adjustable connections of the hinged moldboard have been referred to as being rigid. This is used in the sense that once the moldboard configuration has been selected by manipulation of connection, it is locked in configuration relative to the circle while used in making a cut.

It is important to note that the hinged blade is supported at three locations. The spaced guide brackets hold the wings on either side of the hinged connection, the latter being supported from the circle through the hydraulic jack. This allows the structure to take the additional loading placed on the blade in some V configurations.

We claim:

1. In combination with a motor grader circle having a pair of shank arms, a hinged moldboard unit comprising:

a pair of blade wings joined endwise in a hinged connection;

slide means mounted longitudinally on said blade wings;

two guide means on opposite sides of said hinge connection, each slidably receiving said slide means of its associated blade wing;

a jack means connected between one of said guide means and its associated blade wing for slidably locating said blade wing relative to its guide means;

two mount means, each swingably supporting one of said guide means about an axis parallel with the axis of the said hinged connection and each of said mount means being pivotally connected to the foot of said shank arms of said circle with pivot axis transverse to that of said hinged connection; and

extensible and retractable means connected between said hinge connection and said circle whereby said hinged connection can be positively positioned relative to said circle.

2. The combination as defined in claim 1 wherein adjustable locating means are connected to said mount means to pivot them relative to their associated shank arm.

3. The combination as defined in claim 2 wherein the adjustable locating means include hydraulic jacks which pivotally move said mount means in unison.

4. The combination as defined in claim 1 wherein the slide means mounted longitudinally on the blade wings include rail means which are slidably received in the guide means for holding said hinged moldboard.

5. The combination as defined in claim 1 wherein the extensible retractable means connected between the hinged connection and the circle includes a hydraulic jack which is universally connected to said hinge connection and gimbally supported from said circle.

6. The combination as defined in claim 5 wherein said circle includes a support structure mounted thereon to gimbally support between the shank arms the extensible and retractable means.

References Cited UNITED STATES PATENTS 2,428,131 9/1947 Ue'belhoer 172802 3,241,254 3/1966 Ulrich 37-44 3,258,864 7/1966 Beyers 371l7.5

ROBERT E. PULFREY, Primary Examiner.

E. H. EICKHOLT, Assistant Examiner.

US. Cl. X.R. 

